Obviously there are many ways different hair types can be worn, combed, braided, cut, etc., but is natural, untouched Black/African decendent or ancestry hair an afro like in the 70s or was that styling? I imagine if it is natural, it’s normally like any hair cut shorter to make it easier to manage so that’s why one might see many lengths?
I heard once that there is more human genetic diversity within Africa than the rest of the world combined. Even without that, it’s a big place. So there are probably many many answers to your question, unless you can make it more specific.
It's indeed true. African populations have the highest levels of genetic variation among all humans. Studies of these populations are used to understand demographic changes in Africa and to identify disease-related genes (e.g., APOL1).